In immunochromatography analysis, antibodies (or antigens) which provoke a antigen or antibody reaction with antigens (or antibodies) in a subject (sample) are previously coated in strips onto prescribed positions of an immunochromatography test piece. After applying a subject to an immunochromatography test piece, the antigens (or antibodies) in the subject are dissolved out using a developer solution, and are caused to impregnate into the immunochromatography test piece, whereupon the antigens (or antibodies) in the subject are trapped by an antigen or antibody reaction in the region of the antigens (or antibodies) coated onto the immunochromatography test piece. Since the quantity trapped is the total amount of that antigen (or antibody) in the subject, it is possible to measure the total amount of the antigen (or antibody) by means of optical measurement, such as light absorption, or the like, if the antigen (or antibody) in the subject is previously marked by a dye. Immunochromatography analysis can be used for measuring extremely small quantities, compared to standard calorimetric methods.
Japanese Patent Laid-open No. H7-5110 discloses a measuring device for measuring the concentration of a specific material in a subject from an immunochromatography test piece after development and dying of the subject. In the measuring device described in Japanese Patent Laid-open No. H7-5110, light from an LED is irradiated onto an immunochromatography test piece, the light reflected from the immunochromatography test piece is detected by a CCD color image sensor, and the degree of coloration is identified.